Youtube linky

This a boring video of my 8hp Briggs and Stratton engine that I need to do a quick tune-up on. Can't really afford to spend much cash on it. The engine starts okayish and idles well etc. It doesn't seem to want to rev very well at all when there is a load applied. The spark plug is black as anything and becomes black very quick after a clean up.

Does anyone have any advice/instructions on how to set the carb up and a method of doing this. Also the choke seems to just flap around where it wants to (I think there is either a locking nut missing or even a arm that links into the throttle somehow). Does anyone have any thoughts on this?

Thanks in advance

are you edward needle nose hands?



A vid of it running might help, showing the problem

My first guess would be partially blocked main jet (assuming the carb is like every other carb I've come across)

Stripping a single carb is pretty easy, you dont have to worry about syncing them afterwards etc.

If you cant be faffed at least drop the jets out, poke em with a bit of mig wire and blow through with a air line (or your mouth if you dont have one) Check it up to the light before/after.

Reasemble and check it.

I have no idea about the igntion on one of these so I wont even guess

Is the black on the plug sooty or oily, if oily you may need to reseat the valve or change a stem seal (if it has them - again not sure about the config of the motor).

When my B&S started behaving strangely I found mention on the web of a diaphragm in the carb, I bought one online and it has started and ran well ever since .

Briggs and Stratton carbs have very fine mesh filter below the main jet that is very prone to choking, carefully remove the carb soak the carb with carb cleaner (really cellulose thinners) floor a couple of minutes let it drip for a while and blow through with lowsure air line.

Is taking these carbs apart a difficult job? I don't want to take it apart, bodge something up and have it run worse than before.

What ? , compared to building a kit car? , Stop It!!!!!!

Hmm but I get the impression that Carbs are a bit like witchcraft!

Carb info

pit bike carb (also single cylinder) - but same principle and very detailed

http://www.youtube.com/watch?v=BakwC3VoEGo

Only problem is he insists on calling at a "carby" - which is annoying